Loaders are used for aircraft servicing and are designed to transfer containers, pallets, luggage and other types of goods to aircrafts. Many of the existing loaders have an elevator platform, a bridge platform for interfacing the elevator platform to the aircraft cargo bay, and a control station for controlling operation of the loader.
Different safety mechanisms have been proposed in the art to improve the safety of the operators working on the loader. For example, longitudinal guardrails extending along the bridge platform have been proposed for preventing falling of the operator. Known in the art, there is U.S. Pat. No. 3,524,563 granted to Mc Cartney et al. which describes hand rails mounted on each longitudinal side of the bridge platform and acting as a safety feature for the operators. Each hand rail may be pivoted to a horizontal out-of-the-way position when vertical clearance is needed.
Other retractable guardrails extending under the raised platforms for preventing an operator accessing below the platforms when they are raised have also been proposed. US patent application published under No. 2006/0104760 describes such a system.
In fact, when an operator loads goods inside or outside the aircraft, he generally stands on the bridge platform and is not still aware of the movement of the elevator platform behind him. This movement could be dangerous for the operator since he can fall from the bridge platform when the elevator platform extends at a lower level.
In an attempt to remedy to this issue, in international patent application published under No. WO2006/063453, the applicant of the present invention proposed a retractable handrail mechanism mounted along an end of the bridge platform, between the elevator platform and the bridge platform. The retractable handrail mechanism has an extended position wherein the handrails are raised across the goods path for blocking passage of the goods between the bridge platform and the elevator platform. The retractable handrails also has a retracted position wherein the handrails are moved away from the goods path when both platforms extend at the same level for allowing passage of the goods between both platforms. The retractable handrail mechanism is advantageously responsive to the movement of the elevator platform and is provided with a handrail retracting mechanism for operating the handrails between each of the extended and retracted positions. As described, the handrails may vertically fold on itself. It is also mentioned that a weight-and-pulley device or a pivoting device for vertically lowering the handrails below the bridge platform when both platforms extend at the same level could be used.
This system improves over the prior art in providing a controllable guardrail preventing falling of the operator from the bridge platform to the elevator platform when both platforms do not extend at the same level. The proposed system however remains quite complicate to implement.
It would therefore be desirable to provide an improved barrier system for a loader that will provide a guardrail between the bridge platform and the elevator platform for preventing falling of an operator when the two platforms do not extend at the same level. It would also be desirable that such a barrier system be easy to implement while its design fulfils safety regulations in the field of aircraft loaders. It would be even more desirable to provide a barrier system that would be responsive to the movement of the elevator platform, thereby providing a secure system that will not be time consuming for the operator.